Alongside its new Lumia 950 and Lumia 950 XL flagships, Microsoft also launched a much more affordable Windows 10 Mobile handset - the Lumia 550 - which went on sale in various markets last week. In the UK, the 550 is priced at £99 SIM-free, but it's been available for less on contract-free pay-as-you-go (PAYG) plans.

Until now, the lowest price available had been via leading independent retailer Carphone Warehouse, which was selling the device for £69.99 when purchased with a new £10 PAYG SIM, bringing the total cost to £79.99.

However, just one week after it first went on sale, Carphone Warehouse has now cut that price by £10. That means that you can now buy the Lumia 550 for £69.99 all-in - £59.99 for the handset, plus a £10 PAYG pack on EE (including 150 minutes of cross-network calls, 500MB of 4G data, and unlimited texts).

You can also buy the Lumia 550 with PAYG SIMs and credit on other networks, but the total cost will be at least £15 higher, and given that almost every phone sold by Carphone Warehouse is network-unlocked anyway, you may as well go for the cheapest option with EE.

If you're already a PAYG user, you can pick up the Lumia 550 for even less. The retailer has also dropped the cost of PAYG upgrades by £10, and is now offering the device on upgrade with Vodafone for just £49.99, or with O2 and Virgin Media for £59.99.

The Lumia 550's key specs include:

4.7-inch LCD with HD (1280x720px) resolution

Quad-core 1.1GHz Qualcomm Snapdragon 210 processor

1GB RAM

8GB onboard storage (plus microSD card support up to 200GB)

5MP rear camera with auto-focus and LED flash (720p video recording at 30fps)

2MP front-facing camera (VGA video)

Wi-Fi 802.11 b/g/n

Bluetooth 4.1

USB 2.0 with Type-B connector

4G LTE connectivity

nanoSIM

2100mAh battery

136.1 x 67.8 x 9.9mm; 142g

There's no indication anywhere on the retailer's site that this is part of a special offer or short-term promotion - but that doesn't necessarily mean that this is a permanent price cut. So if you're thinking of buying the 550 at its current price, it may be best not to think about it for too long. Either way, though - permanent or not - it's certainly surprising to see a 12.5% price reduction on a device that's only been on sale for a few days.

It's also worth noting that Carphone Warehouse is the only UK retailer to be offering the Lumia 550 in white. If you'd prefer to buy the 550 elsewhere, you can get it in any colour as long as it's black.